Pattern cam ejector mechanism

ABSTRACT

A pattern cam ejecting mechanism is disclosed associated with a cam follower retracting device. The mechanism is organized so as to be stable in the cam ejected position with the cam followers maintained retracted thus freeing the operators hands for cam manipulation. The pressure incident to insertion of a selected cam on to the cam seat automatically shifts the mechanism out of the stable cam ejected position and returns the cam followers into cam tracking relationship.

United States Patent 1 I Coulombe PATTERN CAM EJECTOR MECHANISM [75]Inventor: Lionel J. Coulombe, Matawan, NJ.

[73] Assignee: The Singer Company, New York,

22 Filed: Jan. 16, 1973 [21] Appl. No.: 324,009

52] use] .Q ..1l2/158A [511 lnt.C1 .tnosb 3/02 [58] Field of Search1l2/12l.11, 158 R, 158 A, 112/158 B; 74/54, 567

[56]. References Cited UNITED STATES PATENTS 3,091,200 5/1963 Fukunaga112/158 A 3,054,368 9/1962 Bono 112/158 X 3,435,788 Fresand et al.112/158 A Apr. l6, 1974 1/1972 Gegauf 112/158 B 4/1973 Daman 74/54Primary Examiner-Werner H. Schroeder Attorney, Agent, or Firm-MarshallJ. Breen; Chester A. Williams, .lr.; Robert E. Smith [5 7] ABSTRACT Apattern cam ejecting mechanism is disclosed associated with a camfollower retracting device. The mechanism is organized so as to bestable in the cam ejected position with the cam followers maintainedretracted thus freeing the operators hands for cam manipulation. Thepressure incident to insertion of a selected cam on to the cam seatautomatically shifts the mechanism out of the stable cam ejectedposition and returns the cam followers into cam tracking relation: ship.

4 Claims, 7 Drawing Figures PATENTEDAPR 16 m4 SHEU 1 UF 3 FATENTEDAPR 119 3804.041

SHEET 2 [IF 3 l PATTERN CAM EJECTOR MECHANISM BACKGROUND OF THEINVENTION Pattern cam ejection mechanisms are known in the art which arenot associated with follower retracting devices. My prior US. Pat. No.3,457,887, July 29, 1969 discloses such an ejection mechanism. Where asingle cam follower is involved, the problem of cam followerinterference with cam exchange is not a serious one, and usually thefollower may be deflected easily by a movement of the cam during camexchange.

Where two or more cam tracks and a corresponding plurality of followersare employed, however, retraction of the followers becomes essential inorder to facilitate cam exchange. A separate operator influenced controlmay be used to effect such follower retraction, but then cam exchangebecomes unduly complicated. Moreover, where one hand of the operatormust be occupied to hold the control instrumentality for maintaining thefollowers retracted, manipulation of pattern cams between the sewingmachine and a storage container must be managed with only one hand,which manipulation can become extremely inconvenient.

BRIEF SUMMARY OF THE INVENTION It is an object of this invention toprovide a pattern cam ejecting mechanism with an associated cam followerretracting device worked by a single operator influenced control whichassumes a stable condition in the cam ejected position maintaining thefollowers retracted without further operator manipulation. The mechanismis automatically shifted so as to restore the followers into camtracking relation when a fresh pattern cam is inserted into operativeposition in the sewing machine.

This object is obtained by the provision of a single control dial withnot only a cam surface for working the pattern cam ejector, but alsowith aconnection to a spring loaded cam follower retracting linkage. Thespring loaded cam follower retracting linkage is so connected to thecontrol dial as to apply a retrograde turning movement to the controldial tending to return the control dial to a position to which the camfollowers are fully effective. As the control dial is shifted into'pattern cam ejected position, however, the connection of the followerretracting linkage with the control dial shifts so as remove the turningmoment or to apply a turning moment in the opposite direction to thecontrol dial urging control dial into a stable follower throw-outposition against a fixed stop. Pressure exerted by insertion of a newlyslected pattern cam causes the cam ejector to react with itsco-operating cam surface on a control dial to impart retrograde turningmovement to the dial sufficient to return the connection of the followerretracing linkage back into position in which it will apply retrogradeturning movement to the control dial so as to return the cam followersinto cam tracking relationship.

DESCRIPTION OF THE DRAWINGS A preferred form of this invention isillustrated in the accompanying drawings in which;

FIG. 1 represents a top plan view of an exchangable pattern cammechanism for both needle jogging and position,

work feeding mechanisms of a sewing machine with my FIG. 4 is a frontelevational view of the control dial and cam ejecting lever of FIG. 3,

FIG. 5 is a front elevational view of the control dial and cam followerretracting linkage of FIG. 3,

FIG. 6 is a front perspective view of the pattern cam ejecting lever andcontrol dial showing the position of parts as a fresh pattern cam isabout to be inserted, and

FIG. 7 is a disassembled perspective view of the control dial togetherwith its pivot stud and a detent means to assist in maintaining themechanism in cam ejected position.

Referring particularly to FIGS. 1 and 2 of the drawings a portion of theframe 11 of a sewing machine is illustrated in which is journaled a maindrive shaft 12 of the sewing machine. By means of a crank 13 on the maindrive shaft, operative movements are imparted to a needle thread take updevice 14 and endwise recipro cation is imparted to a needle carryingbar 15. The needle bar is reciprocated .in a gate 16 which is fulcrummedin the machine frame so that the needle bar may be jogged laterally toproduce zigzag stitches. A drive link 17 pivoted at 18 to the needle bargate serves to impart jogging motion to the needle bar from a zigzagactuating mechanism indicated generally at 20 in the drawings.

The zigzagactuating mechanism 20 includes an ocillating bracket 30pivoted to swing about a pivot pin 31 carried by a lever 32 having afulcrum 33 in the machine frame. A cam follower pin 34 on the ocillatingbracket 30 tracks a zigzag pattern cam 35 which is maintained by aspring clip 36 in engagement with an off-center drive pin 37 on a camseat 38 formed on a vertical cam shaft 39 journaled in the machine frame1 1. The cam shaft 39 carries a worm wheel 40 meshing with a worm 41 onthe main drive shaft.

The needle bar drive link 17, which is biased towards the left as viewedin FIG. 2 by a spring 42 stretched between the drive link l7 and themachine frame 11, carries a slide block 43 which engages the right handside of the oscillating bracket 30 as viewed in FIG. 2. A crank pin 44carried by a bight adjusting dial 45 in the machine frame is embraced bya slot 46 in the needle bar drive link 17 and serves to shift the slideblock 43 along the oscillating bracket relatively to the pivot pin 31thereof in order to regulate the bight of zigzag stitches. A linkage47,48 connects the lever 32 with a needle position adjusting dial 49 inthe machine frame by which the needle position to the right, center, orleft of the field of zigzag stitches may be regulated.

As shown in FIGS. 1, 2, and 6, the zigzag pattern cam 35 is formed asthe lower most one of a paired set of cams indicated generally at whichis permanently fastened together and of which the upper cam is a workfeed pattern cam 61. v

The follower mechanism for the work feed pattern cam 61 may be carriedby a support bracket 62 secured by screws 63 in the machine frame 1 l.Pivoted on a fulcrum pin 64 in the support bracket 62 is a feed followerlever 65 to which a cam follower member 66 is adjustably secured by aclamp screw 67. A stop member 68 may be similarly secured by a clampscrew 69 to the feed follower lever to abut the machine frame and thuslimit movement of the feed follower lever in a direction away from thework feed pattern cam 61.

The feed follower lever carries a roller 70 embraced by a bifurcatedextremity 71 of a lever 72 fulcrummed on a pin 73 carried in aregulating slide 74. A spring 75 stretched between the lever 72 and themachine frame 1 1 biases the feed follower lever 65 toward the work feedpattern cam 61.

The lever 72 may be connected with the regulator of any known type ofsewing machine work feed mechanism so that the work feed pattern cam 61can automatically influence the direction and magnitude of work feedbetween successive stitches. This mechanism is particularly adapted toregulate the work feeding movement of a four motion drop feed mechanismof a sewing machine but it is also suitable for use with any other knowntype of sewing machine work feeding mechanism.

A dial journaled on a pin 81 in the machine frame .11 carries aneccentric 82 which is embraced by the regulating slide 74 on which thefulcrum pin 73 for the lever 72 is carried. The regulating slide 74 isformed with a notch 83 which slidably embraces an anchor pin 84 on thesupport bracket 62. By turning the dial 80 the balance between forwardas compared with reverse direction of feed when in cam control feed modemay be regulated and in an extreme position of the dial 80 the camcontrol of the feed regulation may be completely disabled.

With the zigzag and work feed pattern controlled by paired sets ofpattern cams 60, it will be appreciated that the stitch pattern will beproduced by the sewing machine will depend on the particular cam set 60which is inserted in place on the cam shaft seat 38. This inventionprovides a mechanism which by the application of one operator influencedmotion serves to retract both cam followers 66 and 34 out of trackingrelation with the respective pattern cams 61 and 35 and simultaneouslyeject the pattern cam set 60 from the influence of the spring clip 36 onthe cam seat. This mechanism then without further operator influence,will maintain the followers in retracted position in readiness forinsertion of a different selected cam unit 60.

As shown in FIGS. 1, 2 and 7, a control dial is provided for manuallyinfluencing ejection of a cam unit 60 from the cam seat 38. The controldial 90 is rotatable on a bearing sleeve 91 which is clamped to themachine frame by a shoulder screw 92 as shown in FIG. 2. Also clamped infixed position relatively to the machine frame by the shoulder screw isa washer 93 formed with a radial detent flange 94 and a second washer 95having an anchor hole 96 formed therein for one extremity of a coilspring 97. The other extremity of the coil spring 97 is accomodated in asimilar anchor hole 98 formed in a hub 99 on the control dial 90. Thecoil spring 97 biases the dial 90 in a clockwise direction as viewed inFIG. 1 and the detent finger 94 cooperates with a detent notch 100formed atop a cam block 101 on the control dial 90. The detent fingerand co-operating detent notch serve releasably to maintain the controldial in the fully ejected position of the pattern cam unit as shown asFIGS. 3 and 4.

The cam block 101 is formed with a sloping control cam track 102arranged for co-operation with a follower finger 103 which depends froma pattern cam ejecting lever 104. The cam ejecting lever 104 ispivotably supported on a fulcrum pin 105 secured on a bracket 106 heldby a fastening screw 107 on the machine frame. A free end of the patterncam ejector lever 104 is formed with bifurcate arms 108 which straddlethe cam seat 38 on cam shaft 39 and underlie the pattern cam unit 60placed thereon. As the control dial is turned in a counterclockwisedirection as viewed in FIG. 1 into the position shown in FIGS. 3 and 4the control cam track 102 will cause the cam ejector lever to beelevated thus to force the pattern cam upwardly out of influence of thespring clip 36 and off the cam seat 38.

The control dial 90 is also formed with a control cam slot which, asshown in FIGS. 1 and 7, is preferably straight but inclined at a slightangle radially outward from the center of the control dial 90. A block121 may be added on the dial 90 to increase the thickness of the outerwall slot 120.

The control cam slot 120 is tracked by a follower pin 122 depending froma lever arm 123 which is adjustably secured to a lever body 124fulcrummed on a pivot pin 125 carried in the support bracket 62. Theadjustable connection between the lever arm 123 and the lever body 124may include a pivot pin 126 and spaced from the pivot pin a clamp screw127 which is threaded into the lever arm 123 and passes through anelongated slot 128 in the lever body 124. The lever body 124 carries afinger 129 which abuts the feed follower lever 65, and the lever body124 also carries a finger 130 which abuts the oscillating lever 30 ofthe zigzag actuating mechanism 20. The finger 130 is preferrably securedto V the lever body with capacity for limited adjustment thereon as by alocating pin 131 carried by the lever body and engaging an elongatedslot 132 in the finger 130 together with a clamp screw 133 which passesthrough the slot 131 and is threaded into the lever body 124. Theadjustments provided by the fastenings for the lever arm 123 and thefinger 130 provide for a nicety of co-operation and co-ordination of thecam follower retracting mechanism with both the feed and zigzag camfollowers.

When the cam follower retracting linkage 123 124 becomes effective, thereturn springs 75 and 42 will exert a force by way of the lever arm 123and the follower pin 122 and the cam slot 120 on the control dial 90.When the control dial 90 occupies its position as shown in FIG. 1 theforce exerted by the springs 75 and 42 on a control dial will be exertedin the direction of the arrow placed on FIG. 1 and will act to urge thecontrol dial in a clockwise direction as viewed in FIG. 1.

In other words, the result of the spring force will urge,

the control dial into the position shown in FIG. 1 in its extremeclockwise position. When the control dial 90 has been turned in acounterclockwise direction to the fully ejected-position of a patterncam unit 60 as shown in FIG. 3 the relationship between the follower pin122 and the slot 120 in the control dial are changed so that thedirection of the application of the force of the springs 75 and 42 willassume that of a substantially radial direction on the control dial 90as shown by the arrow in FIG. 3 thus exerting little or no influence onturning movement of a control dial. Because of this relationship, themechanism in the fully ejected position of the cam as shown in FIGS. 3and 4 will be a stable position of the parts, and the mechanism willretain this position without additional operator influence.

As illustrated in FIG. 6 when a fresh cam unit 60 is placed over thebifurcated extremity of the cam ejecting lever 104 and a downwardpressure is applied to seat the cam on the cam seat 38, the followerfinger 103 will exert a clockwise direction of turning movement to thecontrol dial 90 because it rests on the steep slope 102 of the camtrack. The turning movement applied to the control dial 90 by theexertion of the fresh cam onto the stack shifts the follower pin 122 ofthe follower retracting linkage along the slot 120 sufficiently to causethe application of the force of the springs 75 and 42 to take adirection increasingly at an inclination to the radial as illustrated inFIG. 3. The springs 75 and 42 therefore will apply an increasingmagnitude of restoring force to the control dial 90 urging continuedclockwise movement of the control dial into the position illustrated inFIG. 1. Insertion of a fresh cam unto the seat 38 of the cam shaft,therefore, will automatically bring into play the return of the camfollowers into tracking relation with the pattern cams of the cam unitwithout the requirement of additional operator attention.

Having set forth the nature of this invention, what is claimed hereinis:

1. in a sewing machine having a pattern cam exchangeable on a camaccommodating seat and tracked by a pattern cam follower biased towardtracking relation with said pattern cam, a pattern cam ejectingmechanism comprising an operator influenced control cam carried on saidsewing machine and shiftable into and out of cam ejecting position, saidcontrol cam being formed with a pattern cam ejecting cam track and apattern cam follower retracting cam track, a cam ejecting lever on saidsewing machine traversing said pattern cam accommodating seat andincluding a follower finger engaging said pattern cam ejecting cam trackof said control cam, pattern cam follower retracting linkage carried onsaid sewing machine and including a follower finger engaging saidpattern cam follower retracting cam track on said control cam, saidfollower finger on said pattern cam follower retracting linkage being soarranged as to engage said cam follower retracting cam track at avarying angle as said control cam is shifted out of cam ejectingposition as to impart to said control cam a restoring force urging saidcontrol cam out of cam ejected position which restoring force increasesin magnitude directly in proportion to the shift of said control cam outof cam ejected position, said follower finger on said cam ejecting leverbeing so arranged as to engage said pattern cam ejecting track at avarying angle as said control cam is shifted out of cam ejectingposition, as to impart upon insertion of a fresh pattern cam on said camaccommodating seat a restoring force urging said control cam out of camejected position which restoring force decreases in magnitude directlyin proportion to the shift of the control cam out of cam ejectedposition.

2. A pattern cam ejecting mechanism as set forth in claim 1 in whichsaid follower finger on said pattern cam follower retracting linkage isso arranged relatively to said cam follower retracting cam track suchthat no restorative force is applied to said control cam in the full camejected position and said restorative force arises only after a discreteincrement of movement of said control cam out of full cam ejectedposition.

3. A pattern cam ejecting mechanism as set forth in claim 2, in whichsaid restorative force applied to said controlcam by the follower fingeron said cam ejecting lever is effective to impart to said control camsaid discrete increment of movement out of full cam ejected position.

4. A pattern cam ejecting cam mechanism as set forth in claim 1, inwhich said operator influenced control cam comprises a dial supportedfor turning movement in said sewing machine, in which said followerfinger on said pattern cam follower retracting linkage tracks a camfollower retracting cam slot formed in said dial, and in which in thefull cam ejected position of said dial, said follower finger occupies aposition in said cam follower retracting cam slot which extendssubstantially tangentially to the pivot axis of said control dial.

1. In a sewing machine having a pattern cam exchangeable on a camaccommodating seat and tracked by a pattern cam follower biased towardtracking relation with said pattern cam, a pattern cam ejeCtingmechanism comprising an operator influenced control cam carried on saidsewing machine and shiftable into and out of cam ejecting position, saidcontrol cam being formed with a pattern cam ejecting cam track and apattern cam follower retracting cam track, a cam ejecting lever on saidsewing machine traversing said pattern cam accommodating seat andincluding a follower finger engaging said pattern cam ejecting cam trackof said control cam, pattern cam follower retracting linkage carried onsaid sewing machine and including a follower finger engaging saidpattern cam follower retracting cam track on said control cam, saidfollower finger on said pattern cam follower retracting linkage being soarranged as to engage said cam follower retracting cam track at avarying angle as said control cam is shifted out of cam ejectingposition as to impart to said control cam a restoring force urging saidcontrol cam out of cam ejected position which restoring force increasesin magnitude directly in proportion to the shift of said control cam outof cam ejected position, said follower finger on said cam ejecting leverbeing so arranged as to engage said pattern cam ejecting track at avarying angle as said control cam is shifted out of cam ejectingposition, as to impart upon insertion of a fresh pattern cam on said camaccommodating seat a restoring force urging said control cam out of camejected position which restoring force decreases in magnitude directlyin proportion to the shift of the control cam out of cam ejectedposition.
 2. A pattern cam ejecting mechanism as set forth in claim 1 inwhich said follower finger on said pattern cam follower retractinglinkage is so arranged relatively to said cam follower retracting camtrack such that no restorative force is applied to said control cam inthe full cam ejected position and said restorative force arises onlyafter a discrete increment of movement of said control cam out of fullcam ejected position.
 3. A pattern cam ejecting mechanism as set forthin claim 2, in which said restorative force applied to said control camby the follower finger on said cam ejecting lever is effective to impartto said control cam said discrete increment of movement out of full camejected position.
 4. A pattern cam ejecting cam mechanism as set forthin claim 1, in which said operator influenced control cam comprises adial supported for turning movement in said sewing machine, in whichsaid follower finger on said pattern cam follower retracting linkagetracks a cam follower retracting cam slot formed in said dial, and inwhich in the full cam ejected position of said dial, said followerfinger occupies a position in said cam follower retracting cam slotwhich extends substantially tangentially to the pivot axis of saidcontrol dial.